Cellular Network Information

ABSTRACT

Techniques are disclosed relating to a mobile device that communicates over short-range networks and long-range networks. In various embodiments, a mobile device includes one or more radios configured to communicate using a plurality of radio access technologies (RATs) including a cellular RAT and a short-range RAT. The mobile device may establish a first connection and a second connection with a network such that the first connection uses the short-range RAT and the second connection uses the cellular RAT. The mobile may collect information about the second connection and communicate the collected information to the network over the first connection. In some embodiments, the information includes a base station identifier, an MCC, an MNC, the cellular RAT and a cellular information age indicating the time since the information about the second connection was collected by the UE.

PRIORITY DATA

This application claims the benefit of U.S. Prov. Appl. No. 62/183,026,filed Jun. 22, 2015, and U.S. Prov. Appl. No. 62/236,566, filed Oct. 2,2015, which are incorporated by reference herein in their entireties.

FIELD

The present application relates to wireless communication, and moreparticularly, to techniques relating to handovers between differentradio access technologies.

DESCRIPTION OF THE RELATED ART

Wireless communication systems are rapidly growing in usage. Further,wireless communication technology has evolved from voice-onlycommunications to also include the transmission of data, such asInternet and multimedia content.

Expanding traffic on mobile networks has increased the need for mobiledata offloading, wherein a mobile device may access carrier-providedservices originally targeted for cellular networks over an alternativewireless network, such as WiFi, one type of wireless local area network(WLAN). One form of mobile data offloading uses the I-WLAN (InterworkingWireless LAN) or SMOG (S2b Mobility based on GTP) architecture to supplycarrier-provided services to the mobile device over WiFi. Thesecarrier-provided services may include VVM (Visual VoiceMail), MMS(Multimedia Messaging Service), SMS (Short Messaging Service) and IMS(IP Multimedia Subsystem).

Thus, a user equipment device (UE), which may also be referred to as amobile device, may communicate using different radio access technologies(e.g., different cellular RATs and/or WLANs) at different times. Invarious situations, the UE and/or the network may initiate handoverbetween different wireless technologies based on various criteria. Forexample, consider a situation in which a UE is being used for a voiceover LTE (VoLTE) phone call outside a residence and the user stepsinside. At this point, the signal strength of the LTE connection maydrop (e.g., because of the roof of the residence) and the signalstrength of a WiFi connection may increase (e.g., because the user iscloser to a WiFi access point). In response, the UE may initiate ahandover from

VoLTE to WiFi while the network may initiate a handover from VoLTE toanother cellular RAT (e.g., a circuit-switched cellular RAT). If thesignal strength of the WiFi connection, however, becomes weak, this mayresult in the UE attempting to frequently hop between the LTE and WiFiconnections causing a deterioration in call quality.

SUMMARY

Embodiments are presented related to a user equipment device (UE) thatis able to perform handovers between long-range wireless networks (e.g.,cellular networks) and short-range wireless networks (e.g., WiFi andBluetooth networks).

In some embodiments, a UE may establish a first connection with anetwork using a short-range RAT and a second connection with the networkusing a cellular RAT. The UE may collect information about the secondconnection using the cellular RAT and communicate the collectedinformation to the network over the first connection using theshort-range RAT. In some embodiments, the information may include one ormore of an identity of the cell the user is being served by including abase station identifier, a mobile country code (MCC), a mobile networkcode (MNC), an indication of the cellular RAT (e.g., 3GPP-E-UTRAN-FDD,3GPP-UTRAN-TDD, 3GPP2-1X, etc.) and a cellular information ageindicating the time since the information about the cell identity wascollected by the UE. In some embodiments, the network may use thisinformation to provide better services to the UE.

This Summary is intended to provide a brief overview of some of thesubject matter described in this document. Accordingly, it will beappreciated that the above-described features are merely examples andshould not be construed to narrow the scope or spirit of the subjectmatter described herein in any way. Other features, aspects, andadvantages of the subject matter described herein will become apparentfrom the following Detailed Description, Figures, and Claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary (and simplified) wireless communicationsystem, according to some embodiments.

FIG. 2 illustrates a mobile device in communication with a cellular basestation and an access point (AP), according to some embodiments.

FIG. 3 illustrates an example block diagram of a mobile device,according to some embodiments.

FIG. 4 illustrates an example block diagram of an access point,according to some embodiments.

FIG. 5 is a block diagram of an example communication system, accordingto some embodiments.

FIG. 6 illustrates various communication components present in someembodiments of the mobile device.

FIG. 7 illustrates some embodiments of a cellular to WiFi handover,which is an example of a UE-initiated handover process.

FIG. 8 illustrates some embodiments of a mobile device that communicatescellular-link information over a short-range wireless link.

FIGS. 9A and 9B illustrate some embodiments of header fields thatinclude link information.

FIGS. 10A-10C illustrate some embodiments of methods associated withcommunicating cellular-link information.

While the features described herein are susceptible to variousmodifications and alternative forms, specific embodiments thereof areshown by way of example in the drawings and are herein described indetail. It should be understood, however, that the drawings and detaileddescription thereto are not intended to be limiting to the particularform disclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the subject matter as defined by the appended claims.

The term “configured to” is used herein to connote structure byindicating that the units/circuits/components include structure (e.g.,circuitry) that performs the task or tasks during operation. As such,the unit/circuit/component can be said to be configured to perform thetask even when the specified unit/circuit/component is not currentlyoperational (e.g., is not on). The units/circuits/components used withthe “configured to” language include hardware—for example, circuits,memory storing program instructions executable to implement theoperation, etc. Reciting that a unit/circuit/component is “configuredto” perform one or more tasks is expressly intended not to invoke 35U.S.C. §112(f) for that unit/circuit/component.

DETAILED DESCRIPTION

The present disclosure describes embodiments in which a mobile devicemay collect information about a cellular link and communicate thatinformation over a short-range wireless link to a network provider. Thedisclosure begins with a discussion of an exemplary communication systemincluding various components with respect to FIGS. 1-7. Components of amobile device that may be used to collect and communicate cellular-linkinformation are then descried with respect to FIG. 8. Examples of packetheader fields for communicating information are described in conjunctionwith FIGS. 9A and 9B. Embodiments of methods are lastly discussed withrespect to FIGS. 10A-10C.

Acronyms

The following acronyms are used in the present disclosure.

-   BS: Base Station-   AP: Access Point-   APN: Access Point Name-   LTE: Long Term Evolution-   VoLTE: Voice over LTE-   VOIP: Voice Over IP-   IMS: IP Multimedia Subsystem-   MO: Mobile Originated-   MT: Mobile Terminated-   RAT: Radio Access Technology-   TX: Transmit-   RX: Receive-   WLAN: Wireless Local Area Network-   I-WLAN: Interworking WLAN-   SIP: Session Initiation Protocol-   PDN: Packet Data Network-   PGW: PDN Gateway-   SGW: Serving Gateway-   P-CSCF: Proxy Call Session Control Function-   ePDG: evolved Packet Data Gateway-   IFOM: IP Flow Mobility-   SMOG: S2b Mobility based on GTP-   GTP: GPRS Tunneling Protocol-   GPRS: General Packet Radio Service

Glossary

The following is a glossary of terms used in this disclosure:

Memory Medium—Any of various types of non-transitory memory devices orstorage devices. The term “memory medium” is intended to include aninstallation medium, e.g., a CD-ROM, floppy disks, or tape device; acomputer system memory or random access memory such as DRAM, DDR RAM,SRAM, EDO RAM, Rambus RAM, etc.; a non-volatile memory such as a Flash,magnetic media, e.g., a hard drive, or optical storage; registers, orother similar types of memory elements, etc. The memory medium mayinclude other types of non-transitory memory as well or combinationsthereof. In addition, the memory medium may be located in a firstcomputer system in which the programs are executed, or may be located ina second different computer system, which connects to the first computersystem over a network, such as the Internet. In the latter instance, thesecond computer system may provide program instructions to the firstcomputer for execution. The term “memory medium” may include two or morememory mediums which may reside in different locations, e.g., indifferent computer systems that are connected over a network. The memorymedium may store program instructions (e.g., embodied as computerprograms) that may be executed by one or more processors.

Carrier Medium—a memory medium as described above, as well as a physicaltransmission medium, such as a bus, network, and/or other physicaltransmission medium that conveys signals such as electrical,electromagnetic, or digital signals.

Programmable Hardware Element—includes various hardware devicescomprising multiple programmable function blocks connected via aprogrammable interconnect. Examples include FPGAs (Field ProgrammableGate Arrays), PLDs (Programmable Logic Devices), FPOAs (FieldProgrammable Object Arrays), and CPLDs (Complex PLDs). The programmablefunction blocks may range from fine grained (combinatorial logic or lookup tables) to coarse grained (arithmetic logic units or processorcores). A programmable hardware element may also be referred to as“reconfigurable logic”.

Computer System—any of various types of computing or processing systems,including a personal computer system (PC), mainframe computer system,workstation, network appliance, Internet appliance, personal digitalassistant (PDA), television system, grid computing system, or otherdevice or combinations of devices. In general, the term “computersystem” can be broadly defined to encompass any device (or combinationof devices) having at least one processor that executes instructionsfrom a memory medium.

User Equipment (UE) (or “UE Device”)—any of various types of computersystems or devices which are mobile or portable and which performswireless communications. Examples of UE devices include mobiletelephones or smart phones (e.g., iPhone™, Android™-based phones),portable gaming devices (e.g., Nintendo DS™, PlayStation Portable™,Gameboy Advance™, iPhone™), laptops, PDAs, portable Internet devices,music players, data storage devices, other handheld devices, as well aswearable devices such as wrist-watches, headphones, pendants, earpieces,etc. In general, the term “UE” or “UE device” can be broadly defined toencompass any electronic, computing, and/or telecommunications device(or combination of devices) which is easily transported by a user andcapable of wireless communication.

Mobile Device—any of various types of communication devices, which aremobile and are capable of communicating on a cellular network and anon-cellular network, such as WiFi. A UE is an example of a mobiledevice.

Base Station—The term “Base Station” has the full breadth of itsordinary meaning, and at least includes a wireless communication stationinstalled at a fixed location and used to communicate as part of awireless cellular telephone system or cellular radio system.

Access Point—This term has the full breadth of its ordinary meaning, andat least includes a wireless communication device which offersconnectivity to a wireless local area network (WLAN), such as a WiFinetwork.

WiFi—This term has the full breadth of its ordinary meaning, and atleast includes a wireless local area network technology based on theIEEE (Institute of Electrical and Electronics Engineers) 802.11standards, and future revisions or enhancements to those standards.

Processing Element—refers to various elements or combinations ofelements. Processing elements include, for example, circuits such as anASIC (Application Specific Integrated Circuit), portions or circuits ofindividual processor cores, entire processor cores, individualprocessors, programmable hardware devices such as a field programmablegate array (FPGA), and/or larger portions of systems that includemultiple processors.

Channel/Link—a medium used to convey information from a sender(transmitter) to a receiver. It should be noted that sincecharacteristics of the term “channel” may differ according to differentwireless protocols, the term “channel” as used herein may be consideredas being used in a manner that is consistent with the standard of thetype of device with reference to which the term is used. In somestandards, channel widths may be variable (e.g., depending on devicecapability, band conditions, etc.). For example, LTE may supportscalable channel bandwidths from 1.4 MHz to 20 MHz. In contrast, WLANchannels may be 22 MHz wide while Bluetooth channels may be 1 Mhz wide.Other protocols and standards may include different definitions ofchannels. Furthermore, some standards may define and use multiple typesof channels, e.g., different channels for uplink or downlink and/ordifferent channels for different uses such as data, control information,etc.

Automatically—refers to an action or operation performed by a computersystem (e.g., software executed by the computer system) or device (e.g.,circuitry, programmable hardware elements, ASICs, etc.), without userinput directly specifying or performing the action or operation. Thus,the term “automatically” is in contrast to an operation being manuallyperformed or specified by the user, where the user provides input todirectly perform the operation. An automatic procedure may be initiatedby input provided by the user, but the subsequent actions that areperformed “automatically” are not specified by the user, i.e., are notperformed “manually”, where the user specifies each action to perform.For example, a user filling out an electronic form by selecting eachfield and providing input specifying information (e.g., by typinginformation, selecting check boxes, radio selections, etc.) is fillingout the form manually, even though the computer system must update theform in response to the user actions. The form may be automaticallyfilled out by the computer system where the computer system (e.g.,software executing on the computer system) analyzes the fields of theform and fills in the form without any user input specifying the answersto the fields. As indicated above, the user may invoke the automaticfilling of the form, but is not involved in the actual filling of theform (e.g., the user is not manually specifying answers to fields butrather they are being automatically completed). The presentspecification provides various examples of operations beingautomatically performed in response to actions the user has taken.

FIGS. 1 and 2—Communication System

Turning now to FIG. 1, an exemplary (and simplified) wirelesscommunication system is illustrated, according to some embodiments. Itis noted that the system of FIG. 1 is merely one example of a possiblesystem, and disclosed embodiments may be implemented in any of varioussystems, as desired.

As shown, the example wireless communication system includes a cellularbase station 102 which may communicate over a transmission medium withone or more mobile devices 106A, 106B, etc., through 106N. Each of themobile devices may be, for example, a “user equipment device” (UE) orother types of devices as defined above.

The base station 102 may be a base transceiver station (BTS) or cellsite, and may include hardware that enables wireless cellularcommunication with the UEs 106A through 106N. The base station 102 mayalso be equipped to communicate with a network 100 (e.g., a core networkof a cellular service provider, a telecommunication network such as apublic switched telephone network (PSTN), and/or the Internet, amongvarious possibilities). Thus, the base station 102 may facilitatecommunication between the mobile devices and/or between the mobiledevices and the network 100.

The communication area (or coverage area) of the base station may bereferred to as a “cell.” The base station 102 and the UEs 106 may beconfigured to communicate over the transmission medium using any ofvarious cellular radio access technologies (RATs), also referred to aswireless cellular communication technologies, or telecommunicationstandards, such as GSM, UMTS (WCDMA, TD-SCDMA), LTE, LTE-Advanced(LTE-A), 3GPP2 CDMA2000 (e.g., 1×RTT, 1×EV-DO, HRPD, eHRPD), WiFi, WiMAXetc. A typical wireless cellular communication system will include aplurality of cellular base stations, which provide different coverageareas or cells, with handoffs between cells.

Additionally, the example wireless communication system may include oneor more wireless access points (such as access point 104) which may becommunicatively coupled to the network 100. Each wireless access point104 may provide a wireless local area network (WLAN) for communicationwith mobile devices 106. These wireless access points may comprise WiFiaccess points. Wireless access point 104 may be configured to supportcellular network offloading and/or otherwise provide wirelesscommunication services as part of the wireless communication systemillustrated in FIG. 1.

Cellular base station 102 and other similar base stations, as well asaccess points (such as access point 104) operating according to adifferent wireless communication standard (e.g., WiFi), may thus beprovided as a network which may provide continuous or nearly continuousoverlapping service to mobile devices 106 and similar devices over awide geographic area via one or more wireless communication standards.

Thus, while base station 102 may act as a “serving cell” for a UE 106 asillustrated in FIG. 1, each mobile device 106 may also be capable ofreceiving signals from (and possibly within communication range of) oneor more other cells (which might be provided by other base stations (notshown) and/or wireless local area network (WLAN) access points, whichmay be referred to as “neighboring cells” or “neighboring WLANs” (e.g.,as appropriate), and/or more generally as “neighbors”.

Turning now to FIG. 2, a mobile device 106 (e.g., one of the devices106A through 106N) in communication with both a WiFi access point 104and a cellular base station 102 is illustrated, according to someembodiments. The mobile device 106 may be a device with both cellularcommunication capability and non-cellular communication capability,e.g., WiFi capability, such as a mobile phone, a hand-held device, acomputer or a tablet, a wearable device, or virtually any type ofwireless device.

The mobile device 106 may include a processor that is configured toexecute program instructions stored in memory. The mobile device 106 mayperform any of the method embodiments described herein by executing suchstored instructions. Alternatively, or in addition, the mobile device106 may include a programmable hardware element such as an FPGA(field-programmable gate array) that is configured to perform any of themethod embodiments described herein, or any portion of any of the methodembodiments described herein.

In some embodiments, the mobile device 106 may be configured tocommunicate using any of multiple radio access technologies/wirelesscommunication protocols. For example, the mobile device 106 may beconfigured to communicate using any of various cellular communicationtechnologies, such as GSM, UMTS, CDMA2000, LTE, LTE-A, etc. The mobiledevice may also be configured to communicate using any of variousnon-cellular communication technologies such as WLAN/WiFi, or GNSS.Other combinations of wireless communication technologies are alsopossible.

The mobile device 106 may include one or more antennas for communicatingusing one or more wireless communication protocols or technologies. Inone embodiment, the mobile device 106 might be configured to communicateusing either of CDMA2000 (1×RTT/1×EV-DO/HRPD/eHRPD) or LTE using asingle shared radio and/or GSM or LTE using the single shared radio. Theshared radio may couple to a single antenna, or may couple to multipleantennas (e.g., for MIMO) for performing wireless communications. Ingeneral, a radio may include any combination of a baseband processor,analog RF signal processing circuitry (e.g., including filters, mixers,oscillators, amplifiers, etc.), or digital processing circuitry (e.g.,for digital modulation as well as other digital processing). Similarly,the radio may implement one or more receive and transmit chains usingthe aforementioned hardware. For example, the mobile device 106 mayshare one or more parts of receive and/or transmit chains betweenmultiple wireless communication technologies, such as those discussedabove.

In some embodiments, the mobile device 106 may include separate transmitand/or receive chains (e.g., including separate RF and/or digital radiocomponents) for each wireless communication protocol with which it isconfigured to communicate. As a further possibility, the mobile device106 may include one or more radios, which are shared between multiplewireless communication protocols, and one or more radios, which are usedexclusively by a single wireless communication protocol. For example,the mobile device 106 might include a shared radio for communicatingusing either of LTE or 1×RTT (or LTE or GSM), and separate radios forcommunicating using each of WiFi and Bluetooth. Other configurations arealso possible.

FIG. 3—Mobile Device Block Diagram

Turning now to FIG. 3, an exemplary simplified block diagram of a mobiledevice 106 is illustrated, according to some embodiments. As shown, themobile device 106 may include a system on chip (SOC) 300, which mayinclude portions for various purposes. The SOC 300 may be coupled tovarious other circuits of the mobile device 106. For example, the mobiledevice 106 may include various types of memory (e.g., including NANDflash 310), a connector interface 320 (e.g., for coupling to a computersystem, dock, charging station, etc.), the display 360, cellularcommunication circuitry 330 such as for LTE, GSM, etc., and short-rangewireless communication circuitry 329 (e.g., Bluetooth™ and WLANcircuitry). The mobile device 106 may further comprise one or more smartcards 312 that comprise SIM (Subscriber Identity Module) functionality,such as one or more UICC(s) (Universal Integrated Circuit Card(s)) cards312. The cellular communication circuitry 330 may couple to one or moreantennas, preferably two antennas 335 and 336 as shown. The short-rangewireless communication circuitry 329 may also couple to one or both ofthe antennas 335 and 336 (this connectivity is not shown for ease ofillustration).

As shown, the SOC 300 may include processor(s) 302, which may executeprogram instructions for the mobile device 106 and display circuitry304, which may perform graphics processing and provide display signalsto the display 360. The processor(s) 302 may also be coupled to memorymanagement unit (MMU) 340, which may be configured to receive addressesfrom the processor(s) 302 and translate those addresses to locations inmemory (e.g., memory 306, read only memory (ROM) 350, NAND flash memory310) and/or to other circuits or devices, such as the display circuitry304, cellular communication circuitry 330, short range wirelesscommunication circuitry 329, connector I/F 320, and/or display 360. TheMMU 340 may be configured to perform memory protection and page tabletranslation or set up. In some embodiments, the MMU 340 may be includedas a portion of the processor(s) 302.

In some embodiments, as noted above, the mobile device 106 includes atleast one smart card 312, such as a UICC 312, which executes one or moreSubscriber Identity Module (SIM) applications and/or otherwise implementSIM functionality. The at least one smart card 312 may be only a singlesmart card 312, or the mobile device 106 may comprise two or more smartcards 312. Each smart card 312 may be embedded, e.g., may be solderedonto a circuit board in the mobile device 106, or each smart card 312may be implemented as a removable smart card, an electronic SIM (eSIM)or any combination thereof. Any of various other SIM configurations arealso contemplated.

As noted above, the mobile device 106 may be configured to communicatewirelessly using multiple radio access technologies (RATs). The mobiledevice 106 may be configured to communicate according to a WiFi RATand/or one or more cellular RATs, e.g., such as communicating on bothWiFi and cellular at the same time. For example, the mobile device 106may be communicating on a primary communication channel (such as WiFi),and in response to detected degradation of the primary communicationchannel may establish a secondary communication channel (such as oncellular). The mobile device 106 may operate to dynamically establishand/or remove different primary and/or secondary communication channelsas needed, e.g., to provide the best user experience while attempting tominimize cost.

As described herein, the mobile device 106 may include hardware andsoftware components for implementing the features and methods describedherein. The processor 302 of the mobile device 106 may be configured toimplement part or all of the features described herein, e.g., byexecuting program instructions stored on a memory medium (e.g., anon-transitory computer-readable memory medium). Alternatively (or inaddition), processor 302 may be configured as a programmable hardwareelement, such as an FPGA (Field Programmable Gate Array), or as an ASIC(Application Specific Integrated Circuit). Alternatively (or inaddition) the processor 302 of the mobile device 106, in conjunctionwith one or more of the other components 300, 304, 306, 310, 320, 330,335, 340, 350, 360 may be configured to implement part or all of thefeatures described herein.

FIG. 4—Access Point Block Diagram

Turning now to FIG. 4, an exemplary block diagram of an access point 104is illustrated, according to some embodiments. It is noted that theaccess point 104 of FIG. 4 is merely one example of a possible accesspoint. As shown, the access point 104 may include processor(s) 478,which may execute program instructions for the base station 102. Theprocessor(s) 478 may also be coupled to memory management unit (MMU)476, which may be configured to receive addresses from the processor(s)478 and translate those addresses to locations in memory (e.g., memory472 and read only memory (ROM) 474) or to other circuits or devices.

The access point 104 may include at least one network port 480. Thenetwork port 480 may be configured to couple to a network, such as theInternet, and provide a plurality of devices, such as mobile devices106, access to the network as described above in FIGS. 1 and 2.

The network port 480 (or an additional network port) may also beconfigured to couple to a cellular network, e.g., a core network of acellular service provider. The core network may provide mobility relatedservices and/or other services to a plurality of devices, such as mobiledevices 106. In some cases, the network port 480 may couple to atelephone network via the core network, and/or the core network mayprovide a telephone network (e.g., among other mobile devices servicedby the cellular service provider).

The access point 104 may include at least one antenna 486, and possiblymultiple antennas. The at least one antenna 486 may be configured tooperate as a wireless transceiver and may be further configured tocommunicate with mobile devices 106 via wireless communication circuitry482. The antenna 486 communicates with the wireless communicationcircuitry 482 via communication chain 484. Communication chain 484 maybe a receive chain, a transmit chain or both. The wireless communicationcircuitry 482 and the communication chain 484 may compose a radio. Theradio may be configured to communicate via various wireless local areanetwork standards, including, but not limited to WiFi.

Cellular base station 102 may also be described according to the blockdiagram of FIG. 4, except that communication may be performed using anyof various cellular communication technologies.

FIG. 5—Example Wireless Communication System

Turning now to FIG. 5, according to some embodiments, an exemplarywireless communication system is illustrated. As shown, the mobiledevice 106 may communicate with a cellular network via cellular basestation (BS) 102. The cellular base station 102 may communicate with aServing Gateway (SGW) 510. In some embodiments, the SGW 510 isresponsible for handovers with neighboring base stations. In theillustrated embodiment, SGW 510 couples to a Packet Data Network (PDN)Gateway, or (PGW) 520. As shown, evolved Packet Data Gateway (ePDG) 530operates to interface between the cellular and WiFi networks. PGW 520assigns device IP addresses of the iWLAN tunnel interface and thecellular interface. Together ePDG 530, SGW 510 and PGW 520 make up theevolved packet core (EPC).

As shown, mobile device 106 may also communicate with a WiFi accesspoint (AP) 104, where the WiFi access point presents a WiFi network. TheWiFi access point 104 may couple through a network 505, such as theInternet, to the evolved Packet Data Gateway (ePDG) 530. The ePDG 530 isutilized in the network function of 4G mobile core networks, known asthe evolved packet core (EPC) mentioned above, as well as future mobilenetworks, such as 5G networks. As noted above, the ePDG 530 may act asan interface between the EPC and non-3GPP networks that may use secureaccess, such as WiFi and femtocell access networks.

The PGW may function as an inter-RAT mobility anchor. The PGW 520 maycouple to an IMS (IP Multimedia Subsystem) server. The IMS server mayinclude a computer system with a processor and memory, which performsvarious operations as, described herein. The IMS server may implement anIMS Service Layer 540. The IMS server may also implement a Proxy CallSession Control Function (P-CSCF). The P-CSCF may act as the entry pointto the IMS domain and may serve as the outbound proxy server for themobile device. The mobile device may attach to the P-CSCF prior toperforming MIS registrations and initiating SIP sessions. The P-CSCF maybe in the home domain of the IMS operator, or it may be in the visitingdomain where the mobile device is currently roaming.

The IMS server may couple to other networks such as the public switchedtelephone network (PSTN) or other types of communication networks, e.g.,for communicating with other communication devices, such as a standardPOTS telephone (shown), another mobile device, etc.

FIG. 6—Mobile Device Functionality

Turning now to FIG. 6, exemplary functionality that may be present inthe mobile device 106 is illustrated, according to some embodiments. Asshown, the mobile device 106 may include a RAT block 602 that includes awireless radio manager 604, a communication center (CommCenter) block606, and a WiFi manager block 608. The wireless radio manager 604 may beconfigured to receive various statistics from the communication centerblock 606 and/or the WiFi manager block 608 and determine whether to useone or more of available cellular and WiFi connections based on thestatistics. In one embodiment, the communication block 606 may manage orcontrol

baseband logic 610 (e.g., related to cellular communication), and WiFimanager block 608 may manage or control WiFi radio 612. Although notshown, the RAT block 602 may include a symptoms manager that may reportcurrent connection information (e.g., connection metrics or statistics)to the wireless radio manager 604. Elements of the RAT block 502 may beimplemented as software or firmware executable by a processor.

FIG. 7—Exemplary UE-Initiated Cellular to WiFi Handover

Turning now to FIG. 7, a communication diagram for an exemplary cellularto WiFi handover process 700 is illustrated, according to someembodiments. As shown, this process may be triggered by UE 106 (iRATmanager 604 initiates the handover in the illustrated example).Initially, a call for UE 106 is active on a cellular network, via SGW510. For example, the call may be a VoLTE call utilizing IMS.

Subsequently, iRAT manager 604 triggers a cellular to WiFi handover. Asdiscussed above, iRAT manager 604 may trigger the handover based onvarious metrics or criteria. In some embodiments, RAT block 602 isconfigured to determine and track various metrics for cellular and/orWiFi communications. For example, RAT block 602 may maintain cellularinformation including: reference signal received power (RSRP), signal tonoise ratio (SNR), MAC hybrid automatic repeat request (HARD) packetloss, Packet Data Convergence Protocol (PDCP) discard, and/or radio linkcontrol (RLC) packet loss, etc. RAT block 602 may use various sets ofthese metrics to determine the quality of a cellular connection.Similarly, RAT block 602 may maintain WiFi information including:received signal strength indicator (RSSI), SNR, transmit packet errorrate (TX PER), and/or receive (RX) PER, etc. RAT block 602 may usevarious sets of these metrics to determine the quality of a WiFiconnection. Based on this information, iRAT manager 604 may beconfigured to initiate handovers from cellular to WiFi and vice versa.For example, iRAT manage 604 may initiate a handover to WiFi when itdetermines that a stable WiFi connection has been established with goodsignal strength and that the cellular connection quality is low.

In this illustrated example, the UE attaches with AP 104 (this may occurbefore or after triggering of the handover). Subsequently, in theillustrated embodiment UE 106 sends an Internet Key Exchange (IKE)message IKEv2_SA_NIT to ePDG 530 and receives an IKEv2_SA_INIT_RESPresponse to secure exchange of IKEv2_AUTH message, which is subsequentlyexchanged. A session and bearer are created between ePDG 530 and PGW 520for WiFi communication, and the LTE radio bearer is deleted (astriggered by MME 725 in the illustrated embodiment based on signals fromPGS 520 and SGW 510).

The handover illustrated in FIG. 7 is shown for exemplary purposes andis not intended to limit the scope of inter-RAT handovers in variousembodiments. In various embodiments, a UE may trigger handovers in theother direction (e.g., from WiFi to cellular), between other RATs, etc.

FIG. 8—Collecting and Communicating Cellular Network Information

A mobile device connecting to a cellular network typically communicatesinformation about the cellular link to the device's network carrier.This information can include a base station identifier, a mobile countrycode (MCC), a mobile network code (MNC) and/or other information such asthe type of protocol being used to communicate over the cellular link,time zone information, etc. This information can be important forvarious purposes. For example, a network carrier may use the MCC and MNCto determine whether it has any agreements with another network carrierwhen the mobile device is roaming on that carrier's network. Based onthe presence of a particular agreement, the home carrier may select anappropriate billing rate for the mobile device while it is roaming. Asanother example, the network carrier may use the base station identifierto route an emergency call to the appropriate emergency service provider(e.g., the nearest police dispatch).

Some mobile devices now have the ability to register with a carrier'snetwork over a short-range wireless connection such as a WiFiconnection. When a mobile device establishes such a connection, thedevice may maintain a cellular connection, but no longer sendsinformation about the cellular connection to the carrier—instead, thedevice may send information about the WiFi connection. The inability toreceive information about the cellular connection may prevent thecarrier from providing particular services to the mobile device (or atleast may prevent the carrier from providing services in an optimalmanner).

As will be described below, a mobile device may be configured, invarious embodiments, to collect information about a cellular linkestablished by the mobile device and communicate this information to acarrier when the mobile device is communicating with the carrier using ashort-range radio access technology (RAT) such as WiFi. In someembodiments, this information may include one or more of an identifierfor the base station associated with the cellular link, an MCC, an MNC,an indication of the cellular RAT used to communicate with the basestation, and time stamp information. In some embodiments discussedbelow, this information is included within a packet header field, whichmay be referred herein as a Cellular-Network-Info (CNI) header field.

Turning now in FIG. 8, a block diagram of components in a mobile device106 configured to communicate cellular-link information is depicted,according to some embodiments. In FIG. 8, mobile device 106 includes RATblock 602, which manages radio communications for device 106. RAT block602 may manage cellular connections using a core cellular stack 810 thatprocesses cellular communications. RAT block 602 may also manageconnections with an IP multimedia subsystem (IMS) using an IMS stack820. In various embodiments, layers of stacks 810 and 820 may beimplemented using dedicated circuitry and/or software that resides in amemory of device 106 (e.g., memory 306) and executes on one or moreprocessors (e.g., processors 302). In other embodiments, mobile device106 may be implemented differently than shown in FIG. 8.

Core cellular stack 810 may collect various forms of cellular-linkinformation 812 from radio GSM/LTE circuitry 330. As noted above, insome embodiments, this information 812 includes a base stationidentifier, an MCC, an MNC, and/or an indication of the type of RATbeing used (e.g., “3GPP-UTRAN-TDD,” “3GPP2-1X,” etc.). In someinstances, information 812 may pertain to an active cellular linkestablished with a nearby base station. This active link may currentlybe in use for facilitating traffic (e.g., a voice communication) or maybe idle as the mobile device 106 is merely camping on the base stationawaiting potential traffic. In other instance, information 812 maypertain to a previously active cellular link, which has become severed(e.g., the connection was dropped due to a weak signal strength). Thatis, stack 810 may store information 812 about a cellular link when it isestablished by mobile device 106. Stack 810 may then continue to storethis information 810 after the cellular link is severed, so that it canlater be used by IMS stack 820. Information 812 may be collected whenthe mobile device 106 is connected on a visitor network as well as whendevice 106 is on its home network. In some instances, information 812may be collected separately from (e.g., independent of any need by) IMSstack 820. In other instances, stack 810 may collect information uponrequest from IMS stack 820.

For example, in some embodiments, mobile device 106 may supportreceiving a request from a user to enter a mode (e.g., an “AirplaneMode”) in which cellular communication may be suspended. In response toreceiving the request, mobile device 106 may disable radio GSM/LTE 330.If cellular link information 812, however, is need (e.g., stack 820 isperforming an IMS registration as discussed below), mobile device 106may temporarily enable radio 330 in order for stack 810 to collect theinformation 812. Afterwards, mobile device 106 may disable radio 330again in accordance of the user's request. In another embodiment,however, stack 810 may merely provide cellular link information 812 thatwas previously stored prior to entering the requested mode.

IMS stack 820 may aggregate link information and communicate it tonetwork 100, which may correspond to the home network for device 106(i.e., the network operated by the device's carrier/network provider)or, in some embodiments, may correspond to the network being visited bydevice 106. In one embodiment, this communicated link informationincludes information about the link used to access network 100 (e.g.,the link used to register device 106 with network 100's IMS). In variousembodiments, when the mobile device 106 is connected to network 100 viaa short-range wireless link (e.g., WiFi or Bluetooth), IMS stack 820also communicates cellular link information 812 to network 100. In theillustrated embodiment, stack 820 inserts information about the accesslink into a packet header field shown as a Private-Access-Network-Info(P-ANI) header field 822A. Accordingly, when mobile device hasestablished a WiFi connection with network 100, P-ANI header field 822Amay include information about the WiFi connection. In some embodiments,IMS stack 820 communicates cellular link information 812 within a packetheader field labeled as cellular-network-info (CNI) header field 822Bwhen mobile device 106 is communicating with network 100 viaBluetooth/WLAN radio 329.

In various embodiments, CNI header field 822B may include not onlycellular-link information 812, but also some additional information,which may be useful to network 100. Accordingly, in some embodiments,stack 820 may include timing information associated with the data inheader field 822B. For example, in some embodiments, header field 822Bmay include a cellular-information-age parameter (referred to as“cell-info-age”) that indicates the relative time (e.g., 30 seconds)since cellular-link information 812 was collected by the UE. (“Relative”time stands in contrast to indicating an “absolute” time in which twotimestamps are presented—i.e., a timestamp for the current time and thetimestamp for when information 812 was collected.) This parameter may beused by network 100 to determine how old the cellular information 812carried in header field 822B is. In some embodiments, this parameter isa value indicating a number of seconds. In some embodiments, a headerfield 822B may also include location information for a base stationassociated with the cellular link. In the illustrated embodiment, IMSstack 820 obtains this information from database 830 (discussed below)as location information 832.

In the illustrated embodiments, header fields 822A and 822B are insertedinto Session Initiation Protocol (SIP) packets 824 (i.e., SIP requests)that are communicated to network 100. (In other embodiments, headerfields 822A and 822 may be included in other forms of packets, however.)In some embodiments, packets 824 include SIP REGISTER packets thatrequest registration of the mobile device 106 with an IMS of network100. In such embodiments, these packets 824 may be communicated throughan evolved packet data gateway (ePDG) to a proxy-call session controlfunction (P-CSCF) of network 100. There, P-CSCF may then use informationextracted from header field 822B to, for example, allow/disallow WiFicalling from specific countries or locations within certain counties dueto legal and/or contractual reasons, provide discounted billing fromspecific countries, etc. In some embodiments, packets 824 includeemergency SIP INVITE packets that request establishing a communicationbetween mobile device 106 and an emergency service provider. In suchembodiments, these packets 824 may be communicated through an ePDG to anemergency-call session control function (E-CSCF) via a P-CSCF of network100, where extracted information from header field 822B may be used toroute a communication to a call center for the nearest emergency serviceprovider. In some embodiments, stack 820 may also include CNI headerfields 822B in other types of SIP packets such as any SIP request for anSIP dialog, any subsequent SIP request (except SIP ACK requests and SIPCANCEL requests) or response (except SIP CANCEL responses) within an SIPdialog or any SIP request. In some embodiments, the UE populates theP-Access-Network-Info header field with the current point of attachmentto the IP-CAN as specified for the access network technology. In variousembodiments, a CNI header field 822B may be included in any SIP requestsand/or responses in which P-Access-Network-Info header fields 822A arepresent. Examples of possible contents for various embodiments of headerfields 822 are described below with respect to FIGS. 9A and 9B. In someembodiments, sensitive information included in header fields 822A and/or822B may be removed when set outside a trust domain (e.g., as specifiedin RFC 3325).

Database 830, in some embodiments, is configured to store locationinformation for multiple base stations. This location information may bespecified in any of various formats. For example, in one embodiment,database 830 may map a given base station identifier to a correspondingset of location coordinates for the base station (e.g., latitude andlongitude coordinates for the base station). In some embodiments,database 830 may be a global database that includes location informationfor base stations located in different countries throughout the globe.In such an embodiment, database 830 may also include mobile countrycodes (MCCs) and mobile network codes (MNCs).

In some embodiments, database 830 may support performing a reverselookup. That is, given a particular location, in some embodiments,database 830 may return information about the nearest base station suchas the base station identifier, MCC, and MNC. In some embodiments, thisinformation may be used by a mobile device that does not have cellularcapability. For example, a computer may support the ability tocommunicate with an IMS, but lack a cellular radio. In such embodiments,the computer may query database for information about a nearest basestation. The computer may then communicate this information within a CNIheader field 822B to network 100 in order for network 100 to, forexample, appropriately route an emergency call to a local emergencyresponder.

Database 830 may be maintained by any of various suitable entities.Accordingly, in some embodiments, database 830 may be maintained by andreside within mobile device 106. In other embodiments, database 830 maybe maintained by a cellular carrier. In still other embodiments,database 830 may be maintained by a manufacturer of mobile device 106.Accordingly, although FIG. 8 depicts mobile device 106 as accessingdatabase, in other embodiments, database 830 may be accessible to otherentities such as other mobile devices 106, network providers, governmententities, etc.

FIGS. 9A and 9B—Exemplary Syntax for P-Access-Network-Info (P-ANI) andCellular-Network-Info (CNI) Header Fields

Turning now to FIG. 9A, an example of an Augmented Baukus-Naur Form(ABNF) syntax (discussed in RFC 5234) for a P-ANI header field 822A isdepicted, according to some embodiments. In some embodiments, headerfield 822A is compliant with the P-ANI header field described in RFC7315 (entitled “Private Header (P-Header) Extensions to the SessionInitiation Protocol (SIP) for the 3GPP”). As shown, header field 822Amay include an access-net-spec section, which further includes anaccess-type section, an access-class section, and an access-infosection. The access-type section may identified the RAT being used toestablish the link with network 100. The access-class section mayidentify the class of RAT. The access-info section may include additioninformation such as local-time-zone information, location information,etc. Accordingly, when mobile device 106 is communicating with network100 over WiFi, header field 822A include, for example, an access-typeset to IEEE-802.11 and access-info set to i-wlan-node-id. It is notedthat, although FIG. 9A depicts a particular syntax for header field822A, header field 822A may be implemented differently in otherembodiments.

Turning now to FIG. 9B, an example of an ABNF syntax for the CNI headerfield 822B is depicted, according to some embodiments. As shown, headerfield 822B may include a cellular-net-spec section, which includesaccess-type and cellular-access-info sections. In some embodiments,parameters for these sections may be expressed in a similar manner asparameters used for the P-ANI header field discussed above and discussedin RFC 7315. As shown, header field 822B may also include anextension-access-info parameter, a cgi-3gpp parameter,utran-cell-id-3gpp parameter, ci-3gpp2 parameter, and/or ci-3gpp2-femtoparameter. Header field 822B may also include a cell-info-age.

The cgi-3gpp parameter, in some embodiments, is used if the access-typefield is set to 3GPP-GERAN. The cgi-3gpp parameter may be set to thecell global identity (CGI), which may be obtained from lower layers ofthe UE and may be a concatenation of MCC (3 decimal digits), MNC (2 or 3decimal digits depending on MCC value), location area code (LAC) (4hexadecimal digits) and cell identity (CI) (as described in 3GPP TS23.003 entitled “Numbering, addressing and identification”). In such anembodiment, the cgi-3gpp parameter may be encoded in ASCII as defined inRFC 20 (entitled “ASCII format for Network Interchange”).

The utran-cell-id-3gpp parameter, in some embodiments, is used if theaccess-type field is equal to 3GPP-UTRAN-FDD or 3GPP-UTRAN-TDD. Theutran-cell-id-3gpp parameter may be set to a concatenation of the MCC (3decimal digits), MNC (2 or 3 decimal digits depending on MCC value), LAC(4 hexadecimal digits as described in 3GPP TS 23.003) and the UMTS CI (7hexadecimal digits as described in 3GPP TS 25.331 entitled “RadioResource Control (RRC); Protocol Specification”), obtained from lowerlayers of the UE. The utran-cell-id-3gpp parameter may be encoded inASCII as defined in RFC 20. In some embodiments, the utran-cell-id-3gppparameter may alternatively be set to a concatenation of the MCC (3decimal digits), MNC (2 or 3 decimal digits depending on MCC value),tracking area code (TAC) (4 hexadecimal digits as described in 3GPP TS23.003) and the E-UTRAN Cell Identity (ECI) (7 hexadecimal digits asdescribed in 3GPP TS 23.003). Again, the utran-cell-id-3gpp parametermay be encoded in ASCII as defined in RFC 20. For example, If the MCC is111, MNC is 22, TAC is 33C4 and ECI is 76B4321, thenCellular-Network-Info header field may be Cellular-Network-Info:3GPP-E-UTRAN-FDD; utran-cell-id-3gpp=1112233C476B4321.

The ci-3gpp2 parameter, in some embodiments, is used if the access-typefield is set to 3GPP2-1X. The ci-3gpp2 parameter may be set to the ASCIIrepresentation of the hexadecimal value of the string obtained by theconcatenation of system identification number (SID) (16 bits), networkidentification number (NID) (16 bits), packet zone identification (PZID)(8 bits) and BASE (16 bits as described in 3GPP2 C.S0005-D3) in thespecified order. The length of the ci-3gpp2 parameter may be 14hexadecimal characters in some embodiments. The hexadecimal characters(A through F) may be coded using the uppercase ASCII characters. If theUE does not know the values for any of the above parameters, the UE mayuse the value of 0 for that parameter. For example, if the SID isunknown, the UE may represent the SID as 0×0000. (Note that, in thisexample, the SID value is represented using 16 bits as supposed to 15bits as specified in 3GPP2 C.S0005-D.) As another example, if theSID=0×1234, NID=0×5678, PZID=0×12, BASE_ID=0×FFFF, the ci-3gpp2 valuemay be set to the string 1234567812FFFF.

In some embodiments, the ci-3gpp2 parameter may also be used if theaccess type field is set to 3GPP2-1X-HRPD. In such an embodiment, theci-3gpp2 parameter may be set to the ASCII representation of thehexadecimal value of the string obtained by the concatenation of SectorID (128 bits) and subnet length (8 bits) (as described in 3GPP2C.S0024-B) and Carrier-ID, if available, (as described in 3GPP2 X.S0060)in the specified order. The length of the ci-3gpp2 parameter may be 34or 40 hexadecimal characters depending on whether the Carrier-ID isincluded. The hexadecimal characters (A through F) may be coded usingthe uppercase ASCII characters. For example, if the SectorID=0×12341234123412341234123412341234, Subnet length=0×11, and theCarrier-ID=0×555444, the ci-3gpp2 value may be set to the string1234123412341234123412341234123411555444.

In some embodiments, the ci-3gpp2 parameter may also be used if theaccess-type field is set to 3GPP2-UMB (as described in 3GPP2C.S0084-000). In such an embodiment, the ci-3gpp2 parameter may be setto the ASCII representation of the hexadecimal value of the Sector ID(128 bits as defined in 3GPP2 C.S0084-000). The length of the ci-3gpp2parameter may be 32 hexadecimal characters. The hexadecimal characters(A through F) may be coded using the uppercase ASCII characters. Forexample, if the Sector ID=0×12341234123412341234123412341234, theci-3gpp2 value may be set to the string12341234123412341234123412341234.

The ci-3gpp2-femto parameter, in some embodiments, is used if theaccess-type field is set to 3GPP2-1X-Femto. The ci-3gpp2-femto parametermay be set to the ASCII representation of the hexadecimal value of thestring obtained by the concatenation of the femto mobile switchingcenter identification (MSCID) (24 bit), femto CellID (16 bit), FAPequipment identifier (FEID) (64bit), macro MSCID (24 bits) and macroCellID (16 bits as described in 3GPP2 X.P0059-200) in the specifiedorder. The length of the ci-3gpp2-femto parameter may be 36 hexadecimalcharacters. The hexadecimal characters (A through F) may be coded usingthe uppercase ASCII characters.

In some embodiments, the cell-info-age is a value indicating therelative time since cellular-link information 812 (e.g., informationabout the cell identity) was collected by the UE. In some embodiments,this parameter is expressed as a number of seconds. As one example foran LTE connection, header field 822B may specify Cellular-Network-Info:3GPP-E-UTRAN-FDD; utran-cell-id-3gpp=3102608b3ba1ff70f;cell-info-age=60. As one example for UMTS connection, header field 822Bmay specify Cellular-Network-Info: 3GPP-UTRAN-FDD;utran-cell-id-3gpp=310260de7d04e976c; cell-info-age=60. As one for a GSMconnection, header field 822B may specify Cellular-Network-Info:3GPP-GERAN; cgi-3gpp=310260179501e6; cell-info-age=60. That is, theMCC/MNC for T-Mobile USA is 310/260 and the information about the cellidentity was collected one minute ago. Although not shown, in someembodiments, header field 822B may include addition (or less)information such as the base station identifier, location informationabout the base station, etc.

FIGS. 10A-10C—UE and Database Methods

FIGS. 10A-10C depict some embodiments of methods associated withcommunicating cellular-link information over a short-range wirelesslink.

Turning now to FIG. 10A, a flow diagram of a mobile device method 1000is shown. In various embodiments, method 1000 is performed by a mobiledevice (such as UE 106 via RAT block 602). In some embodiments,performance of method 1000 may allow a network provider/carrier toprovide better services to a user of the mobile device.

In 1010, a mobile device establishes a first connection and a secondconnection with a network such that the first connection uses ashort-range RAT and the second connection uses a cellular RAT.

In 1015, the mobile device collects information about the secondconnection. In some embodiments, the collected information includes oneor more of an identifier for a base station associated with in thesecond connection, a mobile country code (MCC), a mobile network code(MNC), an indication of the cellular RAT and a cellular information ageindicating a time since the information about the second connection wascollected by the UE. In some embodiments, 1015 also includes collectinginformation about the first connection. In some embodiments, 1015 mayinclude determining an identifier for a base station associated with thesecond connection and querying a database (e.g., database 830) forlocation information associated with the identifier. In someembodiments, 1015 may include receiving a request from a user to enter amode in which communication using the cellular RAT is suspended,disabling a radio (e.g., radio 330) associated with the cellular RAT inresponse to the request, determining that collection of the informationabout the second connection is warranted, and temporarily activating theradio to collect the information about the second connection.

In 1020, the mobile device communicates the collected information to thenetwork over the first connection. In some embodiments, the communicatedinformation is encapsulated within a header field (e.g., CNI field 822B)of a session initiation protocol (SIP) packet. In one embodiment, theSIP packet specifies a REGISTER request to register the mobile devicewith a IP multimedia subsystem (IMS). In one embodiment, the SIP packetspecifies an INVITE request to establish a communication between themobile device and an emergency service provider. In some embodiments,1020 includes communicating the SIP packet to a call session controlfunction (CSCF) of the network. In some embodiments, the communicatedinformation includes the location information for the base station. Insome embodiments, the information about the first connection iscommunicated with the information about the second connection (e.g.,within the same packet or packets). In one embodiment, the informationabout the first connection is encapsulated in a P-Access-Network-Infoheader field in compliance with a session initiation protocol (SIP). Invarious embodiments, the mobile device communicates the CNI header fieldin each packet that also includes a P-ANI header field. In someembodiments, the collected information in 1015 is stored andcommunicated in 1020 to the network over the first connection after thesecond connection has been severed.

Turning now to FIG. 10B, a flow diagram of network carrier method 1030is presented. In various embodiments, method 1030 is performed by acarrier that interacts with a mobile device that provides cellular-linkinformation over a short-range wireless link. Method 1030 begins in 1035with a network carrier implementing an IP multimedia subsystem (IMS). In1040, the network carrier receives a request from a mobile device toregister over a WiFi connection. The request may include informationthat identifies a cellular base station in communication with the mobiledevice. In 1045, the network carrier registers the mobile device overthe WiFi connection. In some embodiments, method 1030 may also includethe network carrier determining a location of the mobile device byquerying a database that maintains locations of a plurality of basestations including the identified cellular base station. In someembodiments, method 1030 may include the carrier receiving cellularnetwork information (e.g., a CNI header field) over the short-rangenetwork each time it also receives information about the short-rangenetwork (e.g., a P-ANI header field).

Turning now to FIG. 10C, a flow diagram of database method 1060 ispresented. In various embodiments, method 1060 may be performed by acomputer system that supports a database of location information forbase stations. Method 1060 beings in 1065 with a computer systemmaintaining a database (e.g., database 830) that identifies locationcoordinates for a plurality of cellular base stations. In 1070, thecomputer system receives a request for location coordinates of a basestation, where the request identifies the base station by using a basestation identifier. In some embodiments, the request is received from acellular carrier that received the base station identifier from a mobiledevice via a WiFi connection. In some embodiments, the request isreceived from a mobile device configured to communicate the coordinatesto a cellular carrier over a WiFi connection. In 1075, the computersystem provides the location coordinates of the base station in responseto the request.

It is noted that a method is also contemplated for the inverse mappingof location information to an identifier for a base station as discussedabove. In some embodiments, this method may include a computer systemmaintaining a database that associates location information (e.g.,latitude and longitude coordinates) with base station information. Thismethod may include the computer system receiving a request for a basestation identifier, where the request specifies location information.The method may then include determining a base station nearest to alocation corresponding to the specified location information andreturning an identifier for the base station (or identifiers of multiplenearby base stations, in some embodiments).

Various embodiments of systems and methods for servicing requests forlocation information are contemplated based on the precedingdescription, including, but not limited to, the embodiments listedbelow.

In one embodiment, a method comprises a computer system maintaining adatabase that identifies location coordinates for a plurality ofcellular base stations and the computer system receiving a request forlocation coordinates of a base station. The request identifies the basestation by using a base station identifier. The method further comprisesthe computer system providing the location coordinates of the basestation in response to the request. In some embodiments, the request isreceived from a cellular carrier that received the base stationidentifier from a mobile device via a WiFi connection. In someembodiments, the request is received from a mobile device configured tocommunicate the coordinates to a cellular carrier over a WiFiconnection.

Embodiments of the present disclosure may be realized in any of variousforms. For example, various embodiments may be realized as acomputer-implemented method, a computer-readable memory medium, or acomputer system. Other embodiments may be realized using one or morecustom-designed hardware devices such as ASICs. Other embodiments may berealized using one or more programmable hardware elements such as FPGAs.For example, some or all of the units included in the UE may beimplemented as ASICs, FPGAs, or any other suitable hardware componentsor modules.

In some embodiments, a non-transitory computer-readable memory mediummay be configured so that it stores program instructions and/or data,where the program instructions, if executed by a computer system, causethe computer system to perform a method, e.g., any of a methodembodiments described herein, or, any combination of the methodembodiments described herein, or, any subset of any of the methodembodiments described herein, or, any combination of such subsets.

In some embodiments, a device (e.g., a UE) may be configured to includea processor (or a set of processors) and a memory medium, where thememory medium stores program instructions, where the processor isconfigured to read and execute the program instructions from the memorymedium, where the program instructions are executable to implement anyof the various method embodiments described herein (or, any combinationof the method embodiments described herein, or, any subset of any of themethod embodiments described herein, or, any combination of suchsubsets). The device may be realized in any of various forms.

Although the embodiments above have been described in considerabledetail, numerous variations and modifications will become apparent tothose skilled in the art once the above disclosure is fully appreciated.It is intended that the following claims be interpreted to embrace allsuch variations and modifications.

What is claimed is:
 1. A mobile device, comprising: one or more radiosconfigured to communicate using a plurality of radio access technologies(RATs) including a cellular RAT and a short-range RAT; wherein themobile device is configured to: establish a first connection and asecond connection with a network, wherein the first connection uses theshort-range RAT, and wherein the second connection uses the cellularRAT; collect information about the second connection; and communicatethe collected information to the network over the first connection. 2.The mobile device of claim 1, wherein the collected information includesan identifier for a base station associated with in the secondconnection.
 3. The mobile device of claim 2, wherein the collectedinformation includes an indication of the cellular RAT and a cellularinformation age indicating a time since the information about the secondconnection was collected.
 4. The mobile device of claim 1, wherein thecollected information includes a mobile country code (MCC) and a mobilenetwork code (MNC).
 5. The mobile device of claim 1, wherein the mobiledevice is configured to: encapsulate the communicated information withina header field of a session initiation protocol (SIP) packet.
 6. Themobile device of claim 5, wherein the SIP packet specifies a REGISTERrequest to register the mobile device with a IP multimedia subsystem(IMS).
 7. The mobile device of claim 5, wherein the SIP packet specifiesan INVITE request to establish a communication between the mobile deviceand an emergency service provider.
 8. The mobile device of claim 5,wherein the mobile device is configured to: communicate the SIP packetto a call session control function (CSCF) of the network.
 9. The mobiledevice of claim 1, wherein the mobile device is configured to: collectinformation about the first connection; and communicate a packet thatincludes the information about the first connection and the informationabout the second connection.
 10. The mobile device of claim 9, whereinthe mobile device is configured to: encapsulate the information aboutthe first connection in a P-Access-Network-Info header field incompliance with a Session Initiation Protocol (SIP).
 11. The mobiledevice of claim 1, wherein the mobile device is configured to collect aportion of the information about the second connection by: determiningan identifier for a base station associated with the second connection;and querying a database for location information associated with theidentifier, wherein the database stores location information for aplurality of base stations; and wherein the communicated informationincludes the location information for the base station.
 12. The mobiledevice of claim 11, wherein the location information includes latitudeand longitude positions for the base station.
 13. The mobile device ofclaim 1, wherein the mobile device is configured to: collect theinformation and communicate the information while the second connectionis established.
 14. The mobile device of claim 1, wherein the mobiledevice is configured to: collect the information about the secondconnection while the second connection is established; store thecollected information; and after the second connection has been severed,communicate the stored information to the network over the firstconnection.
 15. The mobile device of claim 1, wherein the mobile deviceis configured to: receive a request from a user to enter a mode in whichcommunication using the cellular RAT is suspended; disable a radioassociated with the cellular RAT in response to the request; determinethat collection of the information about the second connection iswarranted; and temporarily activate the radio to collect the informationabout the second connection.
 16. A mobile device, comprising: a firstradio configured to communicate with a network provider over a cellularlink; a second radio configured to communicate with the network providerover a short-range wireless link; one or more processors; memory havingprogram instructions stored therein that are executable by the one ormore processors to cause the mobile device to perform operationsincluding: retrieving information about a base station associated withthe cellular link; and transmitting the information to the networkprovider over the short-range wireless link.
 17. The mobile device ofclaim 16, wherein the operations further include: registering the mobiledevice with an IP multimedia subsystem (IMS); and transmitting theinformation during the registering, wherein the information is usable bythe network provider to determine a location of the base station. 18.The mobile device of claim 16, wherein the information includes a timestamp identifying when the information about the base station wasretrieved and an indication of a radio access technology used tocommunicate within the base station.
 19. A method, comprising: a networkcarrier implementing an IP multimedia subsystem (IMS); and the networkcarrier receiving a request from a mobile device to register over a WiFiconnection, wherein the request includes information that identifies acellular base station in communication with the mobile device; and thenetwork carrier registering the mobile device over the WiFi connection.20. The method of claim 19, further comprising: the network carrierdetermining a location of the mobile device by querying a database thatmaintains locations of a plurality of base stations including theidentified cellular base station.